Yellow Vaginal Discharge
Hormones can be bastards. Among all the stuff they cause to women is a vaginal discharge. It is mostly caused by high concentration of Estrogen.
Should you be concerned?
As stated on Krenizdravo Website:
Is it (the discharge) Normal?
Yellow discharge after the period does not always have to be a cause for concern, as it is not so unusual, especially if there are no accompanying symptoms. After the period, vaginal canal cleansing occurs naturally. Yellow discharge in that period is a sign that you are fertile and that ovulation is on the horizon.
And now, in case you wonder when your ovulation should happen:
More about the female hormones can be found on netdoctor.